I meant Dop1 (R6) Goon1 (R7).
Cata1 won’t suffice for PVP. Low trot movespeed and uptime. Lackluster E.wave damage. Impale is probably the only pro for going Cata1 but it’s a very situational skill and in group PvP if you want to play fetch, you’ll need high mobility which only lv.10-15 trot can provide (or if there’s a chrono in the team/party).
If going Dopel1 for R6 meant I’d only get the skill DoV, I’d still do it. DoV even at lv.5 is the best skill you can get from an R6 filler in your build. Pop a lapasape and instant +50% DPS output for 30-ish seconds which you can do again after ~10s (that’s 75% uptime). All other skills are just bonuses (though as @razm2888 said, Cyclone’s pretty strong too, great filler).
Off-topic, Corsair is a viable alternative to Dop1 too if you’re PVP-focused.